misc: clean up bmp085 driver

This patch includes various cleaning of the bmp085 driver including:
- Whitespaces and alignment fixes
- Minor typos
- Consistency fixes

Reviewed-by: Stefan Nilsson <stefan.nilsson@unixphere.com>
Signed-off-by: Eric Andersson <eric.andersson@unixphere.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 103 insertions, 103 deletions

diff --git a/drivers/misc/bmp085.c b/drivers/misc/bmp085.c
index 76c3064629f1..6f572bc21879 100644
--- a/drivers/misc/bmp085.c
+++ b/drivers/misc/bmp085.c
@@ -1,62 +1,63 @@
 /*  Copyright (c) 2010  Christoph Mair <christoph.mair@gmail.com>
-
-    This driver supports the bmp085 digital barometric pressure
-    and temperature sensor from Bosch Sensortec. The datasheet
-    is available from their website:
-    http://www.bosch-sensortec.com/content/language1/downloads/BST-BMP085-DS000-05.pdf
-
-    A pressure measurement is issued by reading from pressure0_input.
-    The return value ranges from 30000 to 110000 pascal with a resulution
-    of 1 pascal (0.01 millibar) which enables measurements from 9000m above
-    to 500m below sea level.
-
-    The temperature can be read from temp0_input. Values range from
-    -400 to 850 representing the ambient temperature in degree celsius
-    multiplied by 10.The resolution is 0.1 celsius.
-
-    Because ambient pressure is temperature dependent, a temperature
-    measurement will be executed automatically even if the user is reading
-    from pressure0_input. This happens if the last temperature measurement
-    has been executed more then one second ago.
-
-    To decrease RMS noise from pressure measurements, the bmp085 can
-    autonomously calculate the average of up to eight samples. This is
-    set up by writing to the oversampling sysfs file. Accepted values
-    are 0, 1, 2 and 3. 2^x when x is the value written to this file
-    specifies the number of samples used to calculate the ambient pressure.
-    RMS noise is specified with six pascal (without averaging) and decreases
-    down to 3 pascal when using an oversampling setting of 3.
-
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
+ *  Copyright (c) 2012  Bosch Sensortec GmbH
+ *  Copyright (c) 2012  Unixphere AB
+ *
+ *  This driver supports the bmp085 digital barometric pressure
+ *  and temperature sensor from Bosch Sensortec. The datasheet
+ *  is available from their website:
+ *  http://www.bosch-sensortec.com/content/language1/downloads/BST-BMP085-DS000-05.pdf
+ *
+ *  A pressure measurement is issued by reading from pressure0_input.
+ *  The return value ranges from 30000 to 110000 pascal with a resulution
+ *  of 1 pascal (0.01 millibar) which enables measurements from 9000m above
+ *  to 500m below sea level.
+ *
+ *  The temperature can be read from temp0_input. Values range from
+ *  -400 to 850 representing the ambient temperature in degree celsius
+ *  multiplied by 10.The resolution is 0.1 celsius.
+ *
+ *  Because ambient pressure is temperature dependent, a temperature
+ *  measurement will be executed automatically even if the user is reading
+ *  from pressure0_input. This happens if the last temperature measurement
+ *  has been executed more then one second ago.
+ *
+ *  To decrease RMS noise from pressure measurements, the bmp085 can
+ *  autonomously calculate the average of up to eight samples. This is
+ *  set up by writing to the oversampling sysfs file. Accepted values
+ *  are 0, 1, 2 and 3. 2^x when x is the value written to this file
+ *  specifies the number of samples used to calculate the ambient pressure.
+ *  RMS noise is specified with six pascal (without averaging) and decreases
+ *  down to 3 pascal when using an oversampling setting of 3.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
 
 #include <linux/module.h>
+#include <linux/device.h>
 #include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 
-
+#define BMP085_NAME                     "bmp085"
 #define BMP085_I2C_ADDRESS              0x77
 #define BMP085_CHIP_ID                  0x55
 
 #define BMP085_CALIBRATION_DATA_START   0xAA
 #define BMP085_CALIBRATION_DATA_LENGTH  11      /* 16 bit values */
 #define BMP085_CHIP_ID_REG              0xD0
-#define BMP085_VERSION_REG              0xD1
 #define BMP085_CTRL_REG                 0xF4
 #define BMP085_TEMP_MEASUREMENT         0x2E
 #define BMP085_PRESSURE_MEASUREMENT     0x34
@@ -65,9 +66,6 @@
 #define BMP085_CONVERSION_REGISTER_XLSB 0xF8
 #define BMP085_TEMP_CONVERSION_TIME     5
 
-#define BMP085_CLIENT_NAME              "bmp085"
-
-
 static const unsigned short normal_i2c[] = { BMP085_I2C_ADDRESS,
                                                         I2C_CLIENT_END };
 
@@ -78,20 +76,18 @@ struct bmp085_calibration_data {
         s16 MB, MC, MD;
 };
 
-
-/* Each client has this additional data */
 struct bmp085_data {
-        struct i2c_client *client;
-        struct mutex lock;
-        struct bmp085_calibration_data calibration;
-        u32 raw_temperature;
-        u32 raw_pressure;
-        unsigned char oversampling_setting;
+        struct  i2c_client *client;
+        struct  mutex lock;
+        struct  bmp085_calibration_data calibration;
+        u8      oversampling_setting;
+        u32     raw_temperature;
+        u32     raw_pressure;
+        u32     temp_measurement_period;
         unsigned long last_temp_measurement;
-        s32 b6; /* calculated temperature correction coefficient */
+        s32     b6; /* calculated temperature correction coefficient */
 };
 
-
 static s32 bmp085_read_calibration_data(struct i2c_client *client)
 {
         u16 tmp[BMP085_CALIBRATION_DATA_LENGTH];
@@ -99,12 +95,12 @@ static s32 bmp085_read_calibration_data(struct i2c_client *client)
         struct bmp085_calibration_data *cali = &(data->calibration);
         s32 status = i2c_smbus_read_i2c_block_data(client,
                                 BMP085_CALIBRATION_DATA_START,
-                                BMP085_CALIBRATION_DATA_LENGTH*sizeof(u16),
+                                (BMP085_CALIBRATION_DATA_LENGTH << 1),
                                 (u8 *)tmp);
         if (status < 0)
                 return status;
 
-        if (status != BMP085_CALIBRATION_DATA_LENGTH*sizeof(u16))
+        if (status != (BMP085_CALIBRATION_DATA_LENGTH << 1))
                 return -EIO;
 
         cali->AC1 =  be16_to_cpu(tmp[0]);
@@ -121,7 +117,6 @@ static s32 bmp085_read_calibration_data(struct i2c_client *client)
         return 0;
 }
 
-
 static s32 bmp085_update_raw_temperature(struct bmp085_data *data)
 {
         u16 tmp;
@@ -130,7 +125,7 @@ static s32 bmp085_update_raw_temperature(struct bmp085_data *data)
         mutex_lock(&data->lock);
         status = i2c_smbus_write_byte_data(data->client, BMP085_CTRL_REG,
                                                 BMP085_TEMP_MEASUREMENT);
-        if (status != 0) {
+        if (status < 0) {
                 dev_err(&data->client->dev,
                         "Error while requesting temperature measurement.\n");
                 goto exit;
@@ -163,8 +158,9 @@ static s32 bmp085_update_raw_pressure(struct bmp085_data *data)
 
         mutex_lock(&data->lock);
         status = i2c_smbus_write_byte_data(data->client, BMP085_CTRL_REG,
-                BMP085_PRESSURE_MEASUREMENT + (data->oversampling_setting<<6));
-        if (status != 0) {
+                        BMP085_PRESSURE_MEASUREMENT +
+                        (data->oversampling_setting << 6));
+        if (status < 0) {
                 dev_err(&data->client->dev,
                         "Error while requesting pressure measurement.\n");
                 goto exit;
@@ -193,7 +189,6 @@ exit:
         return status;
 }
 
-
 /*
  * This function starts the temperature measurement and returns the value
  * in tenth of a degree celsius.
@@ -205,7 +200,7 @@ static s32 bmp085_get_temperature(struct bmp085_data *data, int *temperature)
         int status;
 
         status = bmp085_update_raw_temperature(data);
-        if (status != 0)
+        if (status < 0)
                 goto exit;
 
         x1 = ((data->raw_temperature - cali->AC6) * cali->AC5) >> 15;
@@ -222,8 +217,10 @@ exit:
 /*
  * This function starts the pressure measurement and returns the value
  * in millibar. Since the pressure depends on the ambient temperature,
- * a temperature measurement is executed if the last known value is older
- * than one second.
+ * a temperature measurement is executed according to the given temperature
+ * measurement period (default is 1 sec boundary). This period could vary
+ * and needs to be adjusted according to the sensor environment, i.e. if big
+ * temperature variations then the temperature needs to be read out often.
  */
 static s32 bmp085_get_pressure(struct bmp085_data *data, int *pressure)
 {
@@ -234,16 +231,16 @@ static s32 bmp085_get_pressure(struct bmp085_data *data, int *pressure)
         int status;
 
         /* alt least every second force an update of the ambient temperature */
-        if (data->last_temp_measurement == 0 ||
-                        time_is_before_jiffies(data->last_temp_measurement + 1*HZ)) {
+        if ((data->last_temp_measurement == 0) ||
+            time_is_before_jiffies(data->last_temp_measurement + 1*HZ)) {
                 status = bmp085_get_temperature(data, NULL);
-                if (status != 0)
-                        goto exit;
+                if (status < 0)
+                        return status;
         }
 
         status = bmp085_update_raw_pressure(data);
-        if (status != 0)
-                goto exit;
+        if (status < 0)
+                return status;
 
         x1 = (data->b6 * data->b6) >> 12;
         x1 *= cali->B2;
@@ -274,15 +271,14 @@ static s32 bmp085_get_pressure(struct bmp085_data *data, int *pressure)
 
         *pressure = p;
 
-exit:
-        return status;
+        return 0;
 }
 
 /*
  * This function sets the chip-internal oversampling. Valid values are 0..3.
  * The chip will use 2^oversampling samples for internal averaging.
  * This influences the measurement time and the accuracy; larger values
- * increase both. The datasheet gives on overview on how measurement time,
+ * increase both. The datasheet gives an overview on how measurement time,
  * accuracy and noise correlate.
  */
 static void bmp085_set_oversampling(struct bmp085_data *data,
@@ -309,12 +305,16 @@ static ssize_t set_oversampling(struct device *dev,
         struct i2c_client *client = to_i2c_client(dev);
         struct bmp085_data *data = i2c_get_clientdata(client);
         unsigned long oversampling;
-        int success = strict_strtoul(buf, 10, &oversampling);
-        if (success == 0) {
+        int err = kstrtoul(buf, 10, &oversampling);
+
+        if (err == 0) {
+                mutex_lock(&data->lock);
                 bmp085_set_oversampling(data, oversampling);
+                mutex_unlock(&data->lock);
                 return count;
         }
-        return success;
+
+        return err;
 }
 
 static ssize_t show_oversampling(struct device *dev,
@@ -322,6 +322,7 @@ static ssize_t show_oversampling(struct device *dev,
 {
         struct i2c_client *client = to_i2c_client(dev);
         struct bmp085_data *data = i2c_get_clientdata(client);
+
         return sprintf(buf, "%u\n", bmp085_get_oversampling(data));
 }
 static DEVICE_ATTR(oversampling, S_IWUSR | S_IRUGO,
@@ -337,7 +338,7 @@ static ssize_t show_temperature(struct device *dev,
         struct bmp085_data *data = i2c_get_clientdata(client);
 
         status = bmp085_get_temperature(data, &temperature);
-        if (status != 0)
+        if (status < 0)
                 return status;
         else
                 return sprintf(buf, "%d\n", temperature);
@@ -354,7 +355,7 @@ static ssize_t show_pressure(struct device *dev,
         struct bmp085_data *data = i2c_get_clientdata(client);
 
         status = bmp085_get_pressure(data, &pressure);
-        if (status != 0)
+        if (status < 0)
                 return status;
         else
                 return sprintf(buf, "%d\n", pressure);
@@ -386,25 +387,23 @@ static int bmp085_detect(struct i2c_client *client, struct i2c_board_info *info)
 
 static int bmp085_init_client(struct i2c_client *client)
 {
-        unsigned char version;
-        int status;
         struct bmp085_data *data = i2c_get_clientdata(client);
+        int status = bmp085_read_calibration_data(client);
+
+        if (status < 0)
+                return status;
+
         data->client = client;
-        status = bmp085_read_calibration_data(client);
-        if (status != 0)
-                goto exit;
-        version = i2c_smbus_read_byte_data(client, BMP085_VERSION_REG);
         data->last_temp_measurement = 0;
+        data->temp_measurement_period = 1*HZ;
         data->oversampling_setting = 3;
         mutex_init(&data->lock);
-        dev_info(&data->client->dev, "BMP085 ver. %d.%d found.\n",
-                        (version & 0x0F), (version & 0xF0) >> 4);
-exit:
-        return status;
+
+        return 0;
 }
 
 static int __devinit bmp085_probe(struct i2c_client *client,
-                         const struct i2c_device_id *id)
+                        const struct i2c_device_id *id)
 {
         struct bmp085_data *data;
         int err = 0;
@@ -415,14 +414,11 @@ static int __devinit bmp085_probe(struct i2c_client *client,
                 goto exit;
         }
 
-        /* default settings after POR */
-        data->oversampling_setting = 0x00;
-
         i2c_set_clientdata(client, data);
 
         /* Initialize the BMP085 chip */
         err = bmp085_init_client(client);
-        if (err != 0)
+        if (err < 0)
                 goto exit_free;
 
         /* Register sysfs hooks */
@@ -430,8 +426,9 @@ static int __devinit bmp085_probe(struct i2c_client *client,
         if (err)
                 goto exit_free;
 
-        dev_info(&data->client->dev, "Successfully initialized bmp085!\n");
-        goto exit;
+        dev_info(&client->dev, "Successfully initialized %s!\n", BMP085_NAME);
+
+        return 0;
 
 exit_free:
         kfree(data);
@@ -441,13 +438,16 @@ exit:
 
 static int __devexit bmp085_remove(struct i2c_client *client)
 {
+        struct bmp085_data *data = i2c_get_clientdata(client);
+
         sysfs_remove_group(&client->dev.kobj, &bmp085_attr_group);
-        kfree(i2c_get_clientdata(client));
+        kfree(data);
+
         return 0;
 }
 
 static const struct i2c_device_id bmp085_id[] = {
-        { "bmp085", 0 },
+        { BMP085_NAME, 0 },
         { }
 };
 MODULE_DEVICE_TABLE(i2c, bmp085_id);
@@ -455,7 +455,7 @@ MODULE_DEVICE_TABLE(i2c, bmp085_id);
 static struct i2c_driver bmp085_driver = {
         .driver = {
                 .owner = THIS_MODULE,
-                .name   = "bmp085"
+                .name   = BMP085_NAME
         },
         .id_table       = bmp085_id,
         .probe          = bmp085_probe,
@@ -467,6 +467,6 @@ static struct i2c_driver bmp085_driver = {
 
 module_i2c_driver(bmp085_driver);
 
-MODULE_AUTHOR("Christoph Mair <christoph.mair@gmail.com");
+MODULE_AUTHOR("Christoph Mair <christoph.mair@gmail.com>");
 MODULE_DESCRIPTION("BMP085 driver");
 MODULE_LICENSE("GPL");